export default {
    data() {
        return {}
    },
    computed: {},
    mounted() {

    },
    methods: {
        dragIcon(e) {
            const dialogHeaderEl = e.target;
            if (e.target.className == 'q-card__section q-card__section--vert row items-center' || e.target.className == 'q-card__section q-card__section--vert row items-center q-pb-none') {
                dialogHeaderEl.style.cssText += ';cursor:move;'
            }
        },
        // 对话框拖动
        dialogDrag(e, i) {
            const dialogHeaderEl = e.target;
            if (e.target.className == 'q-card__section q-card__section--vert row items-center' || e.target.className == 'q-card__section q-card__section--vert row items-center q-pb-none') {
                const dragDom = e.target.parentElement;

                // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
                const sty = (() => {
                    if (window.document.currentStyle) {
                        return (dom, attr) => dom.currentStyle[attr];
                    } else {
                        return (dom, attr) => getComputedStyle(dom, false)[attr];
                    }
                })()

                // 鼠标按下，计算当前元素距离可视区的距离
                const disX = e.clientX - dialogHeaderEl.offsetLeft;
                const disY = e.clientY - dialogHeaderEl.offsetTop;

                const screenWidth = document.body.clientWidth; // body当前宽度
                const screenHeight = document.documentElement.clientHeight; // 可见区域高度(应为body高度，可某些环境下无法获取) 

                const dragDomWidth = dragDom.offsetWidth; // 对话框宽度
                const dragDomheight = dragDom.offsetHeight; // 对话框高度

                const minDragDomLeft = dragDom.offsetLeft;
                const maxDragDomLeft = screenWidth - dragDom.offsetLeft - dragDomWidth;

                const minDragDomTop = dragDom.offsetTop;
                const maxDragDomTop = screenHeight - dragDom.offsetTop - dragDomheight;

                // 获取到的值带px 正则匹配替换
                let styL = sty(dragDom, 'left');
                let styT = sty(dragDom, 'top');

                // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
                if (styL.includes('%')) {
                    styL = +document.body.clientWidth * (+styL.replace(/\%/g, '') / 100);
                    styT = +document.body.clientHeight * (+styT.replace(/\%/g, '') / 100);
                } else {
                    styL = +styL.replace(/\px/g, '');
                    styT = +styT.replace(/\px/g, '');
                };

                document.onmousemove = function(e) {
                    // 通过事件委托，计算移动的距离 
                    let left = e.clientX - disX;
                    let top = e.clientY - disY;

                    // 边界处理
                    if (-(left) > minDragDomLeft) {
                        left = -(minDragDomLeft);
                    } else if (left > maxDragDomLeft) {
                        left = maxDragDomLeft;
                    }
                    if (-(top) > minDragDomTop) {
                        top = -(minDragDomTop);
                    } else if (top > maxDragDomTop) {
                        top = maxDragDomTop;
                    }

                    // 移动当前元素  
                    dragDom.style.cssText += `;left:${left + styL}px;top:${top + styT}px;`;
                };

                document.onmouseup = function(e) {
                    document.onmousemove = null;
                    document.onmouseup = null;
                };
            }
        },
    }
}